The present invention relates to an elastic hinge for eyeglasses.
It is well-known that elastic hinges for eyeglasses are currently commercially available which have temples provided, at the hinge engagement ends, with an eyelet-shaped element which in turn engages two other mutually parallel elements which have the same eyelet-like shape and protrude from the front of the eyeglasses.
The articulation of each hinge is provided by means of a pivot which engages the eyelet-shaped elements of the front of the eyeglasses, between which the eyelet-shaped element of the temple is arranged.
The temple is usually also provided with a slider which is characterized by a substantially cylindrical body having a spoon-shaped end.
The slider is arranged so that its spoon-shaped end abuts against the eyelet-shaped elements of the front through the action of a spring.
The spring is usually accommodated inside an elongated hollow body which is fitted on the temple.
The elongated hollow body constitutes an element for protecting the spring, which thus remains invisible from outside, and at the same time acts as a contrast element for the spring, so that the spring makes the slider abut against the eyelet-shaped element of the temple.
The elongated hollow body must be fixed to the temple.
The difference among the various kinds of elastic hinge that are currently commercially available is substantially due to the method used to lock the elongated hollow body to the temple.
The hollow body is currently fixed to the temple, in any applications, by welding or gluing.
However, in practical execution there are difficulties linked to the time and precision required by such a process.
In the production of elastic hinges there are in fact complications in terms of construction and process which cause severe slowing due to the difficulty of welding or gluing the elongated hollow body to the temple.
These limitations are observed most of all in the case of hinges obtained with metal temples, since the temples are usually smaller than the others.
In particular, it should be noted that welding operations must be particularly precise and accurate to avoid affecting the aesthetic characteristics of the eyeglasses.
There are also other solutions, in which the hollow body is fixed to the temple by means of a first threaded portion, formed inside said hollow body, and a second threaded portion, which is shaped complementarily to the first portion and is formed along the temple.
However, also this entails a particularly precise and highly accurate process, which is difficult to manage in view of the size of the temples and of the precision required for production.
In addition to the above-mentioned types, there is a type of eyeglasses in which the elongated hollow body is fixed to the temple by mechanical action.
In this type of eyeglasses, the hollow body is locked in its sliding along the temple by means of a compression, performed for example with a punching machine, which deforms and flattens it.
In this case too, however, production complexities are not eliminated.